Galactosemia
Galactose-1-phosphate uridyl transferase deficiency; Galactokinase deficiency; Galactose-6-phosphate epimerase deficiency
Galactosemia is a condition in which the body is unable to use ( metabolize ) the simple sugar galactose.
Metabolize
Metabolism refers to all the physical and chemical processes in the body that convert or use energy, such as:BreathingCirculating bloodControlling bo...
Causes
Galactosemia is an inherited disorder. This means it is passed down through families. If both parents carry a nonworking copy of the gene that can cause galactosemia, each of their children has a 25% (1 in 4) chance of being affected with it.
There are 3 forms of the disease:
- Galactose-1 phosphate uridyl transferase deficiency: Classic galactosemia, the most common and most severe form
- Deficiency of galactose kinase
- Deficiency of galactose-6-phosphate epimerase
People with galactosemia are unable to fully break down the simple sugar galactose. Galactose makes up half of lactose, the sugar found in milk.
If an infant with galactosemia is given milk, substances made from galactose build up in the infant's system. These substances damage the liver, brain, kidneys, and eyes.
People with galactosemia cannot tolerate any form of milk (human or animal). They must be careful about eating other foods containing galactose.
Symptoms
Infants with galactosemia can develop symptoms in the first few days of life if they eat formula or breast milk that contains lactose. The symptoms may be due to a serious blood infection with the bacteria E coli .
Symptoms of galactosemia are:
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Convulsions
Convulsions
A seizure is the physical findings or changes in behavior that occur after an episode of abnormal electrical activity in the brain. The term "seizure...
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Irritability
Irritability
Young children who cannot talk yet will let you know when something is wrong by acting fussy or irritable. If your child is fussier than usual, it c...
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Lethargy
Lethargy
Fatigue is a feeling of weariness, tiredness, or lack of energy.
- Poor feeding -- baby refuses to eat formula containing milk
- Poor weight gain
- Yellow skin and whites of the eyes (jaundice)
- Vomiting
Exams and Tests
Tests to check for galactosemia include:
-
Blood culture
for bacterial infection (
E coli sepsis
)
Blood culture
A blood culture is a laboratory test to check for bacteria or other germs in a blood sample.
-
Enzyme
activity in the red blood cells
Enzyme
Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For example, they can help break down the foods we eat ...
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Ketones in the urine
Ketones in the urine
A ketone urine test measures the amount of ketones in the urine.
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Prenatal diagnosis by directly measuring the enzyme
galactose-1-phosphate uridyl transferase
Galactose-1-phosphate uridyl transferas
Galactose-1-phosphate uridyltransferase is a blood test that measures the level of a substance called GALT, which helps break down milk sugars in you...
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"Reducing substances" in the infant's urine, and normal or
low blood sugar
while the infant is being fed breast milk or a formula containing lactose
Low blood sugar
Low blood sugar is a condition that occurs when the body's blood sugar (glucose) decreases and is too low. Blood sugar below 70 mg/dL (3. 9 mmol/L) i...
Newborn screening tests in many states check for galactosemia.
Test results may show:
-
Amino acids in the urine or blood plasma
Amino acids in the urine or blood plasm
Aminoaciduria is an abnormal amount of amino acids in the urine. Amino acids are the building blocks for proteins in the body.
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Enlarged liver
Enlarged liver
Hepatomegaly is swelling of the liver beyond its normal size. If both the liver and spleen are enlarged, it is called hepatosplenomegaly.
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Fluid in the abdomen
Fluid in the abdomen
Ascites is the build-up of fluid in the space between the lining of the abdomen and abdominal organs.
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Low blood sugar
Low blood sugar
Low blood sugar is a condition that occurs when the body's blood sugar (glucose) decreases and is too low. Blood sugar below 70 mg/dL (3. 9 mmol/L) i...
Treatment
People with this condition must avoid all milk, products that contain milk (including dry milk), and other foods that contain galactose, for life. Read product labels to make sure you or your child with the condition are not eating foods that contain galactose.
Infants can be fed:
- Soy formula
- Another lactose-free formula
-
Meat-based formula or Nutramigen (a
protein
hydrolysate formula)
Protein
Proteins are the building blocks of life. Every cell in the human body contains protein. The basic structure of protein is a chain of amino acids. ...
Calcium supplements are recommended.
Support Groups
Galactosemia Foundation -- www.galactosemia.org
Outlook (Prognosis)
People who are diagnosed early and strictly avoid milk products can live a relatively normal life. However, mild mental impairment may develop, even in people who avoid galactose.
Possible Complications
These complications can develop:
- Cataracts
-
Cirrhosis
of the liver
Cirrhosis
Cirrhosis is scarring of the liver and poor liver function. It is the last stage of chronic liver disease.
- Delayed speech development
- Irregular menstrual periods, reduced function of ovaries leading to ovarian failure
-
Mental disability
Mental disability
Intellectual disability is a condition diagnosed before age 18 that includes below-average intellectual function and a lack of skills necessary for d...
- Severe infection with bacteria ( E coli sepsis )
- Tremors (shaking) and uncontrollable motor functions
- Death (if there is galactose in the diet)
When to Contact a Medical Professional
Call your health care provider if:
- Your infant has galactosemia symptoms
- You have a family history of galactosemia and are considering having children
Prevention
It is helpful to know your family history. If you have a family history of galactosemia and want to have children, genetic counseling will help you make decisions about pregnancy and prenatal testing. Once the diagnosis of galactosemia is made, genetic counseling is recommended for other members of the family.
Many states screen all newborns for galactosemia. If the newborn test shows possible galactosemia, they should stop giving their infant milk products right away and ask their provider about having blood tests that can be done to confirm a diagnosis of galactosemia.
References
Berry GT, Walter JH. Disorders of galactose metabolism. In: Saudubray JM, van den Berghe G, Walter JH, eds. Inborn Metabolic Diseases: Diagnosis and Treatment . 5th ed. New York, NY: Springer; 2012:chap 7.
Broomfield A, Brain C, Grunewald S. Galactosaemia: diagnosis, management and long-term outcome. Paediatrics and Child Health . 2015:25(3);113-118.
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Galactosemia - illustration
An infant with galactosemia is unable to use (metabolize) the simple sugar galactose, which reaches high levels in the body, causing damage to the liver, central nervous system and various other body systems. An infant with galactosemia may develop jaundice, vomiting, lethargy, irritability and convulsions.
Galactosemia
illustration
-
Galactosemia - illustration
An infant with galactosemia is unable to use (metabolize) the simple sugar galactose, which reaches high levels in the body, causing damage to the liver, central nervous system and various other body systems. An infant with galactosemia may develop jaundice, vomiting, lethargy, irritability and convulsions.
Galactosemia
illustration
Review Date: 4/20/2015
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.